SO Duo is a song project of Sumru Ağıryürüyen and Orçun Baştürk who have been creating various projects together, in a spectrum between traditional and avant-garde since 2013. As SO Duo, they play their own songs basically, writing their own lyrics, and using some texts from ancient/traditional/mystical poetry (from Anatolian sufis like Yunus Emre, minstrels like Aşık Veysel, Lao Tsu, Kabir and from very old Uygur texts about good or bad fortune) as well. Their music, inspired by various styles they love, can be defined as traditional, and minimalistic. Sometimes they take songs from forgotten languages to their repertoire. They have performed in many festivals and events in Turkey, and abroad. Their first album covering their songs Ay Ana/Mother Moon (alt-folk/other) has been released in April 2018 by Kalan Publishing. Their second album The Light (SO Duo ft. Steve Gorn), and their third album Kırksabır / Patience Fruit have been released by BILGI Music Label in 2019, and 2020 respectively.

Sumru is one of the few woman free improviser singers in Turkey. While she is also known for her works in other genres such as folk and rock, Orçun has a reputation as an outstanding drummer, composer and song writer. They are both founding members of leading bands from avant-rock to traditional music in Turkey. Both musicians have performed and collaborated on many projects in many countries.